Spaceframe structures have long been known and applied to special architectural and engineering problems. Spaceframes are hyperstatic structures. They have evolved out of the quest to better utilize the tensile properties of materials in order to achieve higher performance load-carrying capacities in structures. These improved structural characteristics are achieved through the high repetition of a basic, triangulated, self-bracing geometry expressed in a three-dimensional truss-like framework.
In general, spaceframes are lighter in weight than conventional structures and permit longer clear spans without additional vertical supports. Typically, spaceframe structures have been planar in shape and most often applied to roofing and flooring systems.
The main focus of spaceframe design innovation is the design of the connecting means; usually a nodal arrangement which joins together the ends of elongated frame members and which provides for the transfer and distribution of loads in the realized structure.
The advantages of spaceframe design, however, have largely been limited to exotic applications. A review of the field reveals that spaceframes have most often been used in exhibition structures, airports, hotels, banks, and shopping malls. This is primarily due to higher costs for the manufacture and field assembly of spaceframe components compared to other structural techniques. To date, spaceframe technology has neither been widely accepted nor successfully applied to common construction practice. Until costs can be reduced, spaceframe systems will find only few applications in residential, commercial, industrial and agricultural buildings.
Contributing to the cost and limited application of spaceframes are two basic types of problems exhibited by previous spaceframe connectors: (A) the connectors are comprised of too many parts, first to be manufactured and later to be simultaneously handled in an assembly procedure; or (B) the connectors require too many assembly steps during field construction. These problems are further compounded by the highly repetitive geometry which demands close manufacturing tolerances of all parts and which contributes to the time-consuming of frame aligning and connector adjustments during assembly.
Another major limitation of previous approaches to spaceframe design is the lack of variability of possible shapes of spaceframe structures. In order for common building practice to more fully benefit from spaceframe technology, a connecting means should be capable of producing a range of space-enclosing shapes such as curved vaults and upright cylinders. Previous spaceframe connectors require geometric or structural modifications in order to be used for curved spaceframe applications. In addition, these connectors require separate manufacture for each change of angular curvature and each change in structural specification.